The origin of the name of Strangolagalli is uncertain. Some date it back to legendary fights and the coat of arms depicts a rooster and a dog facing each other, about to fight.
In the area there are some Roman remains but the first document that mentions a village dates back to 1097, when the inhabitants took refuge in a small castle in the hills to escape the Barbarian invasions.
Throughout the Middle Ages it was almost always associated with Monte San Giovanni Campano, and it was a possession of the Girini, a local family, then of the Episcopal lordship of Veroli and finally of the lords of Aquino.
At the beginning of the fifteenth century the Colonna family took possession of the castles of the area and for a time the town was subject both to the papacy as well as the King of Naples.
At the beginning of the sixteenth century, Strangolagalli returned under the Papacy and remained so until the unification of Italy.